Radio receiving circuit



July 8, 1941. H, BL l 2,248,521

RADIO RECEIVING CIRCUIT Filed May 22, 1939 Jnven hr Patented July 8, 1941 RADIO RECEIVING CIRCUIT Archie Henry Blue, Christchurch, New Zealand, assignor of ten-sixteenths to Ross Derisley Wood, Christchurch, New Zealand Application May 22, 1939, Serial No. 274,920

1 Claim.

This invention relates to improvements in radio receiving circuits and apparatus, whereby it is possible to amplify full wave radio signals instead of the half wave as amplified in the present receivers.

Among the objects of my invention are: to provide an efiicient circuit having minimum distortion; to provide a combined rectifier and amplifier circuit in which the biases are proper for their respective actions; to provide a combined rectifier and amplifier circuit in which the rectifier and amplifier actions are at maximum efficiency; to provide an efiicient detector and amplifier circuit adapted for push pull circuits; to provide an eflicient full wave detector and amplifier circuit; and to provide a full wave detector and amplifier circuit having a high power output.

Other objects of my invention will be apparent or will be specifically pointed out in the description forming a part of this specification, but I do not limit myself to the embodiment of my invention herein described, as various forms may be adopted within the scope of the claim.

The improved circuit consists of a centre tapped full wave tuning coil, two gang condenser, two rectifiers, power supply, and a full wave speaker transformer. When radio signals are picked up by the aerial and transferred to the full wave coil one half cycle of the wave passes through each coil and is rectified by the rectifier, then it passes on to its respective side or winding of the full Wave speaker transformer. As the speaker receives two impulses from the signals instead of one greater output can be obtained with better tone. The circuit illustrated in the drawing sets forth diagrammatically in the present invention, and will be more particularly described in relation thereto.

Referring to the diagram an aerial I feeds radio signals to an aerial coil 2 wound over a full wave tuning coil 3 and 4 tuned by gang condenser 5 and 6, and rectifiers I and 8, power supply 9, and I0, full wave speaker transformer ll,

[2, and I3, speaker l4, and earth connection I5.

When a radio signal is received over the circuit, one half wave passes through each side of the full wave tuning coil 3 and 4 to be tuned by the gang condenser 5 and 6, and is rectified by the rectifiers 'l and 8. This rectified current in conjunction with the direct current applied by the batteries 9 and I0 flows through the pushpull input circuit ll, I2 and I3, to actuate the loud speaker l4.

Having now particularly described and ascertained the nature of my said invention, and in what manner the same is to be performed. I declare that what I claim is:

In a radio receiving system, an inductance having a center tap, a speaker unit including a transformer having a center tapped primary coil, a conductor connecting said center taps, a rectifier connected between each end of the inductance and an end of said coil, a source of potential connected in series between each rectifier and the coil, tuning condensers connected across each half of the inductance between the center tap and the adjacent end thereof, and a ground connected with said conductor between said condensers and said coil.

ARCHIE HENRY BLUE. 

